I'm an eye doctor. These 5 common habits could be harming your eye health

You might've heard the old saying, "the eyes are the window to the soul." Sometimes your eyes are also the window to your overall health, which is why protecting them is so important.

Taking breaks from staring at screens, wearing the right eyeglasses if you need them and eating a nutritious diet are all basic things we can do each day to help maintain our eye health. But what about bad habits that can harm your eyesight?

We spoke to eye doctors about some of the most common mistakes people make when it comes to eye health and how to avoid them for healthier, happier eyes.

Skipping eye exams if you have good vision

“People think if they have no problems with their vision that they don’t need to see an eye doctor regularly, and that is a huge misconception,” Dr. Christopher Starr, an ophthalmologist at Weill Cornell Medicine, tells TODAY.com.

Even if you have 20/20 vision, it’s important to get routine eye checkups, especially as you get older. Eye exams involve tests to assess your vision and examine parts of the eye for signs of disease — these can be done by an optometrist or ophthalmologist.

"There are a lot of things we can find on an eye exam that can threaten vision but have no symptoms at all or don't affect vision," Starr says. These include glaucoma, a disease that damages the optic nerve and a common cause of irreversible vision loss, he adds.

Your eyes can also hold important information about your health. "Often we detect systemic diseases first on eye exams, like hypertension or diabetes ... even brain tumors," Starr explains.

Eye exam recommendations are based on age and risk factors. Adults between 18 and 39 who are healthy and have good vision should get an eye exam by an ophthalmologist or optometrist at least every two years, according to the American Academy of Ophthalmology.

At age 40, you should get a comprehensive eye exam by an ophthalmologist or doctor of optometry, and depending on these results, you may additional ones in the future. From 40 to 64, if you still have no eye problems, you should continue to get a routine eye exam every two years. After 65, adults with no eye problems should get a routine eye exam at least yearly.

Some people may need more frequent eye exams based on their risk factors and other eye symptoms, the experts note, so always talk to your doctor about how often you need to get your eyes checked.

Rubbing your eyes

Sometimes, there’s nothing more relieving than a good eye rub — but it should not become a habit. “Try not to rub your eyes,” Dr. Bennie Jeng, chair of ophthalmology at the Scheie Eye Institute at Penn Medicine, tells TODAY.com.

“Eye rubbing is very, very common and we often do it without even thinking about it,” says Jeng. However, excessive or continuous eye rubbing can cause irreversible damage and increase the risk of infection from bacteria on your hands, the experts note.

Eye rubbing has also been associated with a condition called keratoconus, Jeng says, which occurs when the cornea becomes thin and misshapen and can lead to blurred vision or light sensitivity, per the Mayo Clinic.

Depending on its severity, keratoconus can be corrected with contact lenses or surgical procedures, says Jeng, adding, “In more rare circumstances, it can result in needing a corneal transplant."

If you find yourself rubbing your eyes often and can't seem to stop, it may be time to see an eye doctor, the experts note.

Not wearing sunglasses enough

One of the biggest mistakes the experts see people make year-round is skimping on eye protection.

Whether it's not wearing the right sunglasses or not wearing them often enough, people often forget how important it is to protect their eyes from ultraviolet (UV) exposure, Dr. Rudrani Banik, an ophthalmologist at New York Eye and Ear Infirmary of Mount Sinai, tells TODAY.com.

In the short term, prolonged UV exposure can cause dryness and irritation or even a sunburn on the eyes, says Banik. An eye sunburn (photokeratitis) can cause painful symptoms and temporary vision loss, per the Cleveland Clinic.

Over time, exposing the eyes UV rays can damage the cornea and lead to cataracts, macular degeneration, vision problems, and cancer on the eyes and eyelids, Starr notes. That's why it's so important to shield your eyes from harmful UVA and UVB rays.

When you buy sunglasses, look for a sticker that says 100% UVA and UVB blocking or UV 400, Banik emphasizes. “If it says either of those two things, you know that you’re getting the right protection. The cost of the sunglasses doesn’t really matter,” Banik adds. Hats with wide brims can offer extra protection.

“Another big misconception is that on overcast days you don’t need sunglasses. ... The UV index can still be high on cloudy days,” says Starr, adding that this includes snowy days, too.

Any time you are spending time outdoors, especially when the UV index is high, you should wear sunglasses. “I always tell my patients (to) think of sunglasses as (daily) sunblock for your eyes,” says Starr.

Overusing the wrong eye drops

If you struggle with red, irritated eyes, eyedrops can offer relief — but the type matters. Some popular eyedrops advertised to relieve redness can actually make symptoms worse, but a surprising number of people overuse them, the experts say.

Eyedrops with vasoconstrictors (such as naphazoline and tetrahydrozoline) can temporarily relieve redness or discomfort but don't treat symptoms, TODAY.com previously reported.

They constrict blood vessels, says Banik, which rapidly reduces redness visually but also restricts blood flow to the eye. "They are not for daily use," she adds.

Prolonged use of vasoconstrictor eyedrops can create a dependency and cause a rebound effect, the experts explain.

"What often ends up happening is people use them all the time, then they get caught up in this bad cycle. ... The more you use it, you end up having to use it every day and then eventually your eyes are always red, and you can’t get rid of it," says Jeng.

Vasoconstrictors should be used only sparingly and if you really need quick relief, such as for a special event where you want whiter eyes, says Jeng.

As an alternative, Banik recommends using artificial tears (which lubricate the eyes) and chilling them in the refrigerator for extra soothing relief.

If you suffer from chronic red, irritated eyes, the experts suggest seeing an eye doctor who can help figure out the cause. If it's allergies, for example, these can be treated with eye drops containing antihistamines, which are safe for daily use, says Banik.

Always talk to a pharmacist if you have questions about the options for eyedrops available at the drugstore.

Sleeping or swimming in contacts

There are certain mistakes that contact lens-wearers just keep making, the experts note.

Even though there are lenses approved by the U.S. Food and Drug Administration for sleeping, it's best to remove them before bed, says Jeng.

"The risk of infection from sleeping in your contact lenses goes up exponentially, whether they're approved for overnight wear or not," Jeng adds. These range from infections that can be treated with antibiotic eyedrops to those requiring a corneal transplant.

Sleeping in your contacts can also lead to corneal ulcers, says Starr, which can cause permanent damage and vision loss.

"My recommendation is never sleep in your contact lenses, unless you want to put yourself at higher risk for infection," says Jeng.

The same applies to contact lenses and swimming. Whether it's chlorinated water in a pool or hot tub, fresh water, or saltwater, your contact lenses need to come out before you get in, says Banik,

Swimming or submerging your head while wearing contacts not only irritates the eyes but also increases the risk of infection. “Water is usually pretty dirty, and the combination of the germs in the water and contact lenses can lead to bad infections that can even cause blindness in the worst-case scenarios," says Starr.

What about chlorinated water? Chlorine does not kill all pathogens, and contact lenses are like a "breeding ground" for certain types of bacteria found in water once they get into the eyes, says Banik.

If you want to be able to see underwater, Banik recommends prescription goggles. Mistakes happen, so if you forget to take your contacts out before diving in, just make sure to take them out as soon as you get out of the water, Banik adds.

This article was originally published on TODAY.com